On 11/24/20 9:27 PM, Christoph Hellwig wrote:
> Switch the block device lookup interfaces to directly work with a dev_t
> so that struct block_device references are only acquired by the
> blkdev_get variants (and the blk-cgroup special case). This means that
> we not don't need an extra reference in the inode and can generally
> simplify handling of struct block_device to keep the lookups contained
> in the core block layer code.
>
> Signed-off-by: Christoph Hellwig <hch@xxxxxx>
For the bcache part, Acked-by: Coly Li <colyli@xxxxxxx>
Thanks.
Coly Li
> ---
> block/ioctl.c | 3 +-
> drivers/block/loop.c | 8 +-
> drivers/md/bcache/super.c | 20 +-
> drivers/md/dm-table.c | 9 +-
> drivers/mtd/mtdsuper.c | 17 +-
> drivers/target/target_core_file.c | 6 +-
> drivers/usb/gadget/function/storage_common.c | 8 +-
> fs/block_dev.c | 195 +++++--------------
> fs/btrfs/volumes.c | 13 +-
> fs/inode.c | 3 -
> fs/internal.h | 7 +-
> fs/io_uring.c | 10 +-
> fs/pipe.c | 5 +-
> fs/quota/quota.c | 19 +-
> fs/statfs.c | 2 +-
> fs/super.c | 37 ++--
> include/linux/blkdev.h | 2 +-
> include/linux/fs.h | 1 -
> 18 files changed, 114 insertions(+), 251 deletions(-)
>
[snipped]
> diff --git a/drivers/md/bcache/super.c b/drivers/md/bcache/super.c
> index a6a5e21e4fd136..c55d3c58a7ef55 100644
> --- a/drivers/md/bcache/super.c
> +++ b/drivers/md/bcache/super.c
> @@ -2380,38 +2380,38 @@ kobj_attribute_write(register, register_bcache);
> kobj_attribute_write(register_quiet, register_bcache);
> kobj_attribute_write(pendings_cleanup, bch_pending_bdevs_cleanup);
>
> -static bool bch_is_open_backing(struct block_device *bdev)
> +static bool bch_is_open_backing(dev_t dev)
> {
> struct cache_set *c, *tc;
> struct cached_dev *dc, *t;
>
> list_for_each_entry_safe(c, tc, &bch_cache_sets, list)
> list_for_each_entry_safe(dc, t, &c->cached_devs, list)
> - if (dc->bdev == bdev)
> + if (dc->bdev->bd_dev == dev)
> return true;
> list_for_each_entry_safe(dc, t, &uncached_devices, list)
> - if (dc->bdev == bdev)
> + if (dc->bdev->bd_dev == dev)
> return true;
> return false;
> }
>
> -static bool bch_is_open_cache(struct block_device *bdev)
> +static bool bch_is_open_cache(dev_t dev)
> {
> struct cache_set *c, *tc;
>
> list_for_each_entry_safe(c, tc, &bch_cache_sets, list) {
> struct cache *ca = c->cache;
>
> - if (ca->bdev == bdev)
> + if (ca->bdev->bd_dev == dev)
> return true;
> }
>
> return false;
> }
>
> -static bool bch_is_open(struct block_device *bdev)
> +static bool bch_is_open(dev_t dev)
> {
> - return bch_is_open_cache(bdev) || bch_is_open_backing(bdev);
> + return bch_is_open_cache(dev) || bch_is_open_backing(dev);
> }
>
> struct async_reg_args {
> @@ -2535,9 +2535,11 @@ static ssize_t register_bcache(struct kobject *k, struct kobj_attribute *attr,
> sb);
> if (IS_ERR(bdev)) {
> if (bdev == ERR_PTR(-EBUSY)) {
> - bdev = lookup_bdev(strim(path));
> + dev_t dev;
> +
> mutex_lock(&bch_register_lock);
> - if (!IS_ERR(bdev) && bch_is_open(bdev))
> + if (lookup_bdev(strim(path), &dev) == 0 &&
> + bch_is_open(dev))
> err = "device already registered";
> else
> err = "device busy";
[snipped]
